Breathalyzer Sensor Technologies

Breathalyzer Sensor Technologies

There are three main technologies to detect alcohol in one's breath sample.

  1. Fuel Cell Sensors

  2. Semiconductor Sensors

  3. Spectrophotometer 

Fuel Cell Sensors

Fuel Cell Breathalyzers offer an extremely high level of accuracy, sensitivity and reliability while being portable and hand held. In over 30 US states, roadside evidential testing is now permitted using approved fuel cell breathalyzers. A fuel cell breathalyzer measures the concentration of alcohol in the breath sample by measuring the amount of electrical voltage that is created when alcohol compounds are being oxidised at by the fuel cell sensors in a reversible reaction. The more alcohol is present the greater voltage the fuel cell generates, leading to a higher reading. Click here for a list of Fuel Cell Breathalyzers available.

Some of the advantages of Fuel Cell technology over Semiconductor technology.

  • Alcohol specific. Semiconductor devices can give positive alcohol readings even when no alcohol is present. They will react to perfume, hairspray, gasoline, cigarette smoke, and breath substances such as acetone and ketones. Fuel Cell Breathalyzers are always and only Alcohol specific.
  • High accuracy. Fuel Cell Breathalyzers are consistently accurate across a wide alcohol concentration range from .000 to .400 BAC. Unlike semiconductor devices, the Fuel Cell Breathalyzers can report 3-digit BAC measurement accuracy because of the precision of its  Fuel Cell Technology. 

  • Calibration stability. Unlike semiconductors which require frequent re-calibration, most fuel cell breathalyzers require recalibration only once per year or 500 uses under normal use. Semiconductor sensors experience more drift. Drift occurs when there is a wider variation of the results over time and accumulated uses.

  • Long working life. Unlike Semiconductor devices that have a shorter life span, Fuel Cell breathalyzers have an expected working life of 3-5 years. 

  • Proven. Fuel cell technology in alcohol testing has been continually refined and improved since its introduction in the 1970s. It is the technology used in portable breath testing by Law Enforcement globally in their stepped up efforts to deter drunken driving.

  • Reliable. Fuel Cell breathalyzers require short startup time and are able to take consecutive readings without breaks. By comparison, a medium range semiconductor breathalyzer like the Alcoscan AL6000 takes up to 20 consecutive samples before a break of 2 hours is required. This is because with each sample being taken the amount of tin dioxide that remains in the sensor decreases. When it has been depleted, the breathalyzer can no longer measure the breath alcohol until it is rested. Atmospheric oxygen will oxidise it again to replenish it over time.

Semiconductor Sensors

Reputable semiconductor breathalyzers offer users an affordable means to measure their breath alcohol with some compromises on reliability and accuracy. Semiconductor technology uses an oxide sensor to measure the reactivity between the tin dioxide (SnO2) in the sensor and the ethanol molecules in the breath sample. When the ethanol molecules come in contact withthe tin dioxide the reaction changes the electrical resistance of thesensor. The semiconductor measures this difference and calculates an estimate of the BAC of the sample.

Below are key advantages semiconductor breathalyzers have

  • Lower cost of manufacturing results in a more affordable device
  • Lesser power is needed to power the sensor allows for highly portable device
  • Low cost and small size positions it well for mass consumer who is looking for a breathalyzer to estimate one's breath alcohol instead of accurate measuring it.

Important note: There are many semiconductor breathalyzers in the market but only a selected group of them is accurate and reliable. The breathalyzers you see on our website are personally tested by us and we guarantee these bring you value and a good degree of accurate and reliability.


Spectrophotometer technology is used in large, table-top breathalyzers often found at police stations. Spectrophotometers work by identifying molecules based on the way they absorb infrared light. The level of ethanol in a sample is singled out and measured, and a subject's alcohol level can then be determined. Such devices cost at least $1,500 and are only available on request.

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